[RESOLVED] check for duplicate throw popup

[golffinder]

Hi

I'm new here and pretty much completely new to php and mysql so go easy on me.

Somehow I have managed to cobble together something that takes some form inputs and puts them in a db, these consist of a username, email, x value, y values, date etc. but now what i want to do is be able to query the db and throw a popup to the user if they are trying to enter a second lot of information, ie what i wnat to do is create a competition but only allow someone to enter once, so if they have already entered the popup say "Sorry you have already entered with this registered username" or similar

Thanks

Nay help will be much appreciated

[kostis12345]

Add a new column in the DB named "entered" or something with default value 0.When you try to insert the form inputs in the DB check if that column for that specific row is 0 or 1.if it is 1 display the popup if it is 0 enter the data.Don't forget to update the "entered" column after inserting the data.

Hope I helped.

[golffinder]

hi

thanks i follow the logic, but i need to have it so it does all this automatically if possible, is this possible. Also you know how i could do it, ie whats the php etc, i don't have a clue, i can add an extra field into the db, i know how to do that but not how to make it default to 0

thanks

[bradgrafelman]

So a user can only add information once? If so, just throw a UNIQUE index on the username column and check [man]mysql_errno/man for the duplicate key error.

[golffinder]

hi

sory bit confused as i don't really understand, is this going to put 2 records in the db but one with an error, see what i want it to do is after someone has had a go a the competition say on monday and on wednesday they decide to have another go, i want the attempt on wednesday to be blokeed from going in the db and inform them with a poup or similar that they have already entered the competition, need it to be all automatic as well so don't have to manually do anything, can this be done with php and some mysql query?

[bradgrafelman]

golffinder wrote:

is this going to put 2 records in the db but one with an error

No; if you have an error in your query, nothing will be done.

[golffinder]

ok think i got it, make unique key on username, then use this php to check for that error thing:
<?php
$link = mysql_connect("localhost", "mysql_user", "mysql_password");

if (!mysql_select_db("nonexistentdb", $link)) {
echo mysql_errno($link) . ": " . mysql_error($link). "\n";
}

mysql_select_db("kossu", $link);
if (!mysql_query("SELECT * FROM nonexistenttable", $link)) {
echo mysql_errno($link) . ": " . mysql_error($link) . "\n";
}
?>

so on return of this error message thing to the original file which posts the data to the db how do i then get it to throw a popup syaing something like "Sorry you have already entered the competition"

[Weedpacket]

Nothing in that code attempts to insert anything into any table. So it's pretty useless if the idea is to insert data into a table, but have it trigger an error if you attempt to insert a record that collides with one that's already there.

[golffinder]

sorry completely lost with that, can you give me an idiots guide as i am an idiot with this stuff.

i found this: don't know if it does it

$result = mysql_query($query);
if($result == false)
{
if(mysql_errno() == 1062)
{
// output duplicate entry error
}
else
{
// some other error occurred, so log it an alert user
}
}
else
{
// looks like it's OK, though you could double-check with mysql_affected_rows()
}

if i try to add the same username in the db as is already there i get this 1062 error appearing

if this above should throw an error on return of this 1062 error code, i think i might have a problem in that the error code is not being returned??